1. Technical Field
The present invention generally relates to a patch for mounting an electronic monitoring device to the inside surface of a pneumatic tire. More particularly, the present invention relates to a patch having an electronic monitoring device encapsulated directly to the patch so that it may be mounted to a tire with the patch.
2. Background Information
Monitoring the internal conditions of a pneumatic tire while the tire is in use on a vehicle is becoming increasingly desired in the art. One problem with this technology is protecting the relatively sensitive electronic monitoring device in the relatively harsh environment inside a tire. Another problem in the art is that the inner surface of a tire does not have surfaces where monitoring devices may be easily mounted in a secure manner.
Protecting monitoring devices against harsh tire conditions has been accomplished in the past by encapsulating the monitoring device in an encapsulation or potting material. The potting material is poured over the monitoring device and fills the voids around the elements of the monitoring device. The material hardens and forms a protective block having a high modulus of elasticity around the elements of the monitoring device. The monitoring device is protected in this manner from the flexing and shock forces experienced in a pneumatic tire.
Rubber patches are also known in the art to mount monitoring devices to the inner surface of a tire. The potted monitoring device has been connected to the patch with adhesive and the patch was then adhered to the innerliner of the tire. Other methods of mounting monitoring devices inside tires include forming a pocket in the tire and placing the monitoring device in the pocket. Other methods have placed a rubber patch over the top of the monitoring device to hold the monitoring device against the tire sidewall.
One problem with these mounting solutions is the relatively high number of steps required to mount the monitoring device to the tire. Another problem is the number of times the monitoring device must be handled prior to mounting inside the tire. More importantly, the users of the monitoring devices desire stronger connections between the monitoring device and the tire.
Another problem in the art occurs when the antenna is mounted in a different substraight than the monitoring device. In these situations, a connection must be formed between the monitoring device and the antenna. An example of this situation is shown in patent application Ser. No. 09/301,781 filed Apr. 29, 1999, which is owned by the Assignee of the present application. In this situation, a pair of connectors are used to form the direct physical connection between the antenna and the monitoring device. The problem that has occurred is that the adhesive used to bond the monitoring device to the patch is forced around the connectors sometimes flowing into the connectors. The art desires a solution to this problem by providing a method of connecting the encapsulated monitoring device to a patch while not fouling the connectors.
In view of the foregoing, the present invention provides a mounted electronic monitoring device ready for mounting to the inside of the tire. The invention solves the problems in the art by directly potting the monitoring device to a rubber attachment patch to form an assembly.
The assembly of the present invention includes a rubber patch having a first surface and a second surface. An electronic monitoring device is positioned adjacent the first surface of the patch with an encapsulation material surrounding at least a portion of the electronic monitoring device. The encapsulation material bonds with the patch to connect the encapsulated monitoring device to the patch.
Another aspect of the invention preferably provides placing the connecting elements used to electrically connect the monitoring device to an antenna embedded within the patch in a location where the connecting elements are surrounded by the encapsulation material.
Another aspect of the invention provides a method for creating the assembly wherein the number of handling steps and fabricating steps are minimized.
The method of the present invention includes the steps of providing a patch having a first surface and a second surface, providing an electronic monitoring device adjacent the first surface of the patch, and encapsulating the electronic monitoring device directly to the first surface of the patch.
An advantage of the invention is that the patch provides a secure mounting platform for the monitoring device that can be readily attached to the innerliner of a pneumatic tire.
Another advantage of the invention is that the connection between the encapsulated monitoring device and the attachment patch does not rely on the strength of an adhesive to connect two separately formed elements.
Another advantage of the invention is that the assembly protects the connections between the antenna and the monitoring device.
Another advantage of the invention is that the connections between the monitoring device and the antenna do not become fouled by adhesive because the antenna and monitoring device are connected before the encapsulation material is poured into the mold.